1. Field of the Invention
The invention relates to an electronic device such as an image pickup device, a light emitting device, or a display device, and a production process of the same. Specifically, the invention relates to an electronic device comprising terminals of a functional element chip, wiring members electrically connected to the terminals, and an encapsulant to fix the functional element chip and the wiring members, and a production process of the same.
2. Related Background Art
As a type of electronic devices, devices are known, which can convert optical information to an electric signal, can convert an electric signal to optical information, can effect light emission or optical modulation with an electric signal, or can change an optical path with an electric signal. As such devices, devices that have a photofunctional element are known. As the photofunctional element, there are known light receiving elements, light emitting elements, DMD (digital micromirror device), and so on.
As an example, an image pickup device having a light-receiving-element array as an electronic device will be described below. Image pickup devices are often incorporated in image input equipments such as video cameras, digital still cameras, or the like. In production of such an image pickup device, after integrated circuits are fabricated on a semiconductor substrate such as a silicon wafer by integrating photodiodes as light receiving elements and CCD, CMOS or the like as drive/read circuits, color filters and micro lenses are formed above an imaging area (effective pixel region) with an acryl material.
Subsequently, the silicon wafer having the integrated circuits, color filters and micro lenses formed thereon is subjected to dicing into chips, the chips are then housed in ceramic packages or the like, and electric connection is then made between the chip and leads by wire bonding or the like. After that, a cap of a glass plate is attached over the package to protect the chip from the atmosphere.
Recently, as miniaturization of image input equipments such as digital cameras has been made, there has been a need to develop smaller and thinner image pickup devices. Approaches to miniaturize image pickup devices are described, for example in Japanese Patent Application Laid-Open No. 7-99214 and U.S. Pat. No. 5,786,589.
FIG. 10 is a sectional view of a prior art image pickup device. The image pickup device shown in FIG. 10 has a glass cap 14, a TAB (tape-automated bonding) tape 11, and an image pickup element chip. Reference numeral 2 denotes a part of a surface of encapsulant 7. Reference numeral 19 denotes a space surrounded by the cap 14 which is a light transmissive protective member, the encapsulant 7 and the semiconductor element chip 10. The space contains air, an inert gas or the like. First, the glass cap 14 is adhered to the TAB tape 11 having a beam lead 12, with an adhesive layer 30 therebetween. A bump 13 is formed on an image pickup element chip to having an effective pixel region 5 image pickup elements (not shown) and microlenses 16 formed thereon, and an anisotropic conductive adhesive 7 is applied to the bump 13 and its periphery by a dispenser or the like. After the TAB tape 11 adhered to the glass cap 14 with the adhesive layer 30 is aligned with the chip 10, the bump 13 and the TAB tape 11 are thermocompression bonded to each other. Thus, the image pickup device shown in FIG. 10 is obtained.
(Technical Problem 1)
However, since the glass cap 14, the adhesive layer 30, and the insulating film 4 and so on are light transmittable, a light incident on a front face of the beam lead 12 made of a lustrous metal may reflect at the face, and the reflected light may further reflect at the respective interfaces to stray into the effective pixel region. When there is such a stray light, the quality of an obtained image is degraded. Further, in display device such as a DMD, a light reflected from a beam lead may also lower the displaying quality.
(Technical Problem 2)
Furthermore, when the TAB tape 11 adhered to the glass cap 14 with the adhesive layer 30 is thermocompression bonded after the alignment, in order to prevent the anisotropic conductive adhesive 7 from intruding into the effective pixel region 5 during the thermocompression bonding, it is attempted to control the amount of application.
However, with the prior art technique, it is difficult in practice to precisely control the application amount of the anisotropical conductive adhesive 7 although attempt is made to prevent the anisotropical conductive adhesive 7 from intruding into the effective pixel region 5. In fact, the inside protrusion of the anisotropical conductive adhesive 7 toward the effective pixel region occurs, as shown in FIG. 11.
Since the intrusion into the effective pixel region 5 is fatal, when the amount of the anisotropical conductive adhesive is reduced to prevent the inside protrusion, both the electrical connection and mechanical bonding strength become insufficient, which may result in opening of the connection portion, break in the beam lead, breakage of the TAB film, or the like, thus lowering the reliability and the production yield of the image pickup device.
It is, therefore, an object of the invention to provide an electronic device that can solve at least the above mentioned technical problem 1 and can suppress the disadvantage due to light reflected from a beam lead, and a production process of the same.
Another object of the invention is to provide an electronic device that can solve at least the above mentioned technical problem 2, has improved reliability, and can be produced at a low cost, and a production process of the same.
Still another object of the invention is to provide an electronic device that can solve the above mentioned technical problems 1 and 2, can suppress the disadvantage due to light reflected from a beam lead, and is highly reliable and inexpensive, and a production process of the same.
A first aspect of the invention is an electronic device comprising a functional element chip having a photofunctional element formed thereon, a wiring member electrically connected to a terminal of the functional element chip, and an encapsulant for fixing the functional element chip and the wiring member,
wherein a light blocking member with an opening portion is provided on a front face side of the wiring member, and
wherein an end of the opening portion is located more inside than an inner end of the wiring member.
A second aspect of the invention is an electronic device comprising a semiconductor chip having an optical semiconductor element formed thereon, a wiring member electrically connected to a terminal of the semiconductor chip, an encapsulant for fixing the semiconductor chip and the wiring member, and a light transmissive protective member,
wherein a light blocking member with an opening portion is provided between a front face of the wiring member and a rear face of the protective member,
wherein an end of the opening portion is located more inside than an inner end of the wiring member, and
wherein the encapsulant is a photo-set resin, and the end of the opening portion and an inner end of the encapsulant align.
A third aspect of the invention is a process of producing an electronic device comprising a functional element chip with a terminal, a wiring member electrically connected to the terminal, an encapsulant for fixing the functional element chip and the wiring member, and a light transmissive protective member, the process comprising the steps of:
disposing a light blocking member with an opening portion between a front face of the wiring member and a rear face of the protective member such that an end of the opening portion is located more inside than an inner end of the wiring member;
providing a photo-setting resin for forming the encapsulant onto the periphery of a connecting portion between the wiring member and the terminal of the functional element chip; and
irradiating a light from the side of a front face of the protective member through the opening portion of the light blocking member to set at least a part of the photo-setting resin.
A forth aspect of the invention is a process of producing an electronic device comprising a first substrate, a second, light transmissive substrate disposed apart from the first substrate, and an encapsulant for fixing the periphery of the first and the second substrates so as to fill a space between the first and the second substrates, comprising the steps of:
disposing a light blocking member with an opening portion on a rear face of the periphery of the second substrate;
disposing a photo-setting resin for forming the encapsulant on the periphery of the first and the second substrates; and
irradiating a light from the side of a front face of the second substrate through the opening portion of the light blocking member to set at least a part of the photo-setting resin.